Firearms

ABSTRACT

An automatic hand firearm includes a unit comprising a trigger box and a hand grip which are in mutual engagement in the firearm casing by hook and pin engagement means, such engagement being maintained by a projecting part of the shoulder support, the latter being held by means of a detachable pin and on removal the shoulder support releases the unit which can then be withdrawn with a rearward disengagement movement.

rte tates atet [111 3,731,417

Moller et al. 1 May 8, 1973 54 FIREARMS 2,780,145 2 1957 Saive ..42 75 c [75] Inventors: Moll, Obemdorf; Dieter Kw 3,323,246 6/1967 Loffler... ..42 7s c terer, Oberndorf, (Neckar), both of Germany [73] Assignee: Heckler 8: Koch Gmblil, Oberndorf/Neckar, Germany [22] Filed: May 12, 1971 [21] Appl. No.: 142,607

[30] Foreign Application Priority Data May 14, 1970 Germany ..P 20 23 545.4

[52] US. Cl. 42/75 C [51] Int. Cl. ..F41c 27/00 [58] Field of Search ..42/75 C [56] References Cited UNITED STATES PATENTS 854,557 5/1907 Benet et a1 ..42/75 C FOREIGN PATENTS OR APPLICATIONS 111,468 7/1967 Norway ..42/75 C Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney-Craig, Antonelli & Hill An automatic hand firearm includes a unit comprising a trigger box and a hand grip which are in mutual engagement in the firearm casing by hook and pin engagement means, such engagement being maintained by a projecting part of the shoulder support, the latter being held by means of a detachable pin and on removal the shoulder support releases the unit which can then be withdrawn with a rearward disengagement movement.

ABSTRACT 7 Claims, 2 Drawing Figures PATENTEDHAY '81915 3.731.417

SHEET 1 0F 2 INVENTORS BY @180 RM y M1994 ATTORNEYS FIREARMS The invention relates to improvements in firearms and particularly an automatic hand firearm especially an automatic rifle with an assembly consisting of a trigger box and a grip member releasably fastened to the under side of the firearm casing, the rear end of which encloses the firearm casing with a portion of U- shape in cross-section and connected to the firearm casing by means of a holding pin.

With a known automatic firearm the shoulder sup port is attached from the rear to the firearm casing and the rear end of the grip member and secured by means of fastening pins one of which also comes into engagement with the grip member. At its forward end the grip member is connected to the firearm casing by means of a fastening pin which is located in the region of the front lower edge of a trigger box arranged in the grip member. After releasing the shoulder support the grip member can be folded downwardly from the firearm casing around the front fastening pin and can be wholly released if necessary by removing the fastening pin from the firearm casing. It is also known to construct the opening for the fastening pin in the forward lower corner of the grip member as a slot in order that impact forces occurring during firing are removed as far as possible from the grip member. The slots provided can also form slots open to the forward edge of the grip member which permits the grip member to be released from the firearm without removing the front fastening pin. I

The grip member must adopt a precisely defined position in reference to the firearm casing since the spacing and position of the trigger device provided, from the breech track or in relation to the terminal position of the breech track in the direction of the closure movement is of great importance for satisfactory operation of the firearm. With the known rifles the position of the grip member is determined by the front fixing pin and by the position of a rearward projection which is surrounded by the cover-like front portion of the shoulder support and is retained at'the lower side of the firearm casing.

In order that with this arrangement of the fastening the correct position of the trigger device is obtained relatively to the firearm casing, both the widely spaced bearing points on the firearm casing, namely the bore for the fastening pin at the forward end of the grip member and the bearing surface for the rearward projection of the grip member and likewise the corresponding portion of the grip member itself, must be produced with high accuracy. The maintenance of close tolerances requires very careful machining and is consequently costly. The necessity of maintaining such close tolerances conflicts with the attempts at reducing the costs of such firearms by the use of the sheet pressing techniques. It is in the application of pressing techniques on the other hand that the maintenance of very close tolerances is particularly difficult.

A further disadvantage of the known automatic firearms consists in the fact that apart from the fastening pin required for retaining the shoulder support a further fastening pin must be removed from the front end of the grip member if the latter is to be released from the firearm. Removable parts have the disadvantage that they can easily be lost during servicing operations on the firearm which may have serious consequences especially in field use. If the grip member has at the forward end a forwardly open slot instead of a bore for the fastening pin there is the disadvantage that the grip member is no longer retained after releasing the shoulder support but can fold downwardly and then slide off the front fastening pin and fall to the ground. Therefore damage or soiling of the grip member can easily occur which makes the firearm useless or requires thorough cleaning so that such an arrang ement is not very suitable for field use.

The invention is directed to the problem of avoiding these disadvantages of the known firearms as regards the arrangement of the trigger assembly consisting of the trigger box and the grip member, and toarrange this assembly as well as the associated parts of the firearm casing that fixing of the assembly in the desired position is possible without maintaining very close tolerances, and moreover the number of fastening elements required for fastening the grip member, and which have to be removed, is reduced.

This object is attained according to the invention by the fact that the assembly is provided in the region of its upper edge and at the front and rear ends, with a hook extending in the firing direction, and these hooks fit over a catch member fitted in each case to the firearm casing and that the assembly is moreover provided with bearing surfaces in the region of its upper edge which bear against counter surfaces of the firearm casing which determine both the spacing of the assembly from the breech track and also the position in relation to the breech track.

The hooks provided at the front and rear end of the assembly permit satisfactory fixing of the assembly in reference to the firearm casing without requiring a fastening pin at the forward end of the grip member. The hooks can be made inherently slightly springy so that the stop surfaces provided on the assembly bear under a certain pressure against the counter surfaces of the firearm casing which leads to a friction connection which holds the assembly to the firearm casing even when a fastening pin securing the rear end of the grip member to the firearm casing is removed. Since the top surfaces are provided on the assembly in the region of the upper edge thereof the position of which is determined in relation to the firearm casing, these fastening points are not liable to tolerances but form directly the reference lines for the bearing positions of the trigger device so that coarse tolerances are sufficient which can easily be maintained.

Since the tolerances are important in relation to the function of the trigger device and the parts of the trigger device are supported in a trigger box fitted to the grip member, a preferred embodiment of the invention provides that the assembly rests by the upper edge of the side walls of its trigger box against the lower edge of the side walls of the firearm casing so that this trigger box immediately adopts an exactly defined position but does not in fact approach the position of the grip member.

In this way the tolerances to be maintained are particularly uncritical. It is then also particularly convenient to provide a stop on the firearm casing against which the trigger box bears at its front wall.

In a further arrangement of the invention the hook located at the forward end of the assembly can be formed in a particularly simple way by a projection at the upper edge of the front wall of the firearm box and this projection can engage a corresponding recess on the firearm casing. It is therefore convenient for the hook located at the rear end of the assembly, to be formed by a portion of the rear wall of the trigger box which is extended upwardly over the side walls and bend forwardly and fits over a pin connecting the walls of the firearm casing. In fact this hook can be of spring construction and provides in connection with the natural spring of the firearm casing a fixed engagement of the edges of the trigger box to the lower edges of the side walls of the firearm casing, which can be provided with projecting bearing points.

Further details and constructions of the invention are to be seen from the following description in which the invention is further described and explained on the basis of the constructional example shown in the drawing. The features taken from the description and the drawing can be applied in other embodiments of the invention singly on their own or several of them in desired combination.

In the drawings:

FIG. 1 shows a side view of an automatic rifle according to the invention, and

FIG. 2 shows partially in side view and partially in section the assembly of the rifle according to FIG. 1, comprising the grip member and the trigger box, with the associated parts of the firearm casing and the shoulder support.

The firearm shown in the drawing embodies an assembly consisting of a grip member 1 and a trigger box 8 which is secured in the region between the magazine duct 2 and the shoulder support 3 on the under side of the firearm casing 4.

The grip member 1 comprises the hand grip proper 5, the trigger loop 6 and a box-like portion 7 extending upwardly from the grip member and the trigger loop, in which the trigger box 8 is inserted. This trigger box embodies at the lower edge of its front wall a projection 9 with an inwardly extending ledge 10 which engages a corresponding recess in the grip member 1 and is moreover secured in known manner by a safety spindle in a manner not further described traversing the grip member 1 and the trigger box 8, which is rotatable for securing the firearm and for adjusting various types of firing by means of the safety lever 11.

For fastening the assembly comprising the grip member 1 and the trigger box 8 to the firearm casing 4 two hooks 12 and 13 are used both of which extend in the direction towards the magazine duct 2. The forward hook 12 is formed by a projection at the upper edge of the front wall of the trigger box 8. This hook 12 fits over a stop ledge 14 arranged on the side of the magazine duct 2 facing the grip member 1 and bears on the front face 15 of the trigger box 8 so that the position of the trigger box 8 is precisely determined in the firing direction of the firearm. The second hook 13 is formed by a forwardly angled upper end of a portion 16 of the rear wall of the trigger box 8 the side walls 17 of which embody at this point a recess 18.

This hook 13 fits over a pin 19 which connects together the side walls of the firearm casing 4. The

hook 13 therefore engages between the walls 20 of the firearm casing 4 which extend downwardly at this point.

Furthermore the walls 20 of the firearm casing 4 lie opposite the walls of the trigger box 8 and the walls of the trigger box 8 bear at their upper edges against the lower edges of the walls of the downwardly open firearm casing above the trigger box 8. For this purpose special bearing faces 21 are provided at the lower edges of the walls of the firearm casing 4 near the front and the rear edge of the trigger box 8. The position of the bearing faces 21 in relation to the stop ledge 14 on the magazine duct 2 as well as the position of the hooks 12 and 13 is so chosen in relation to the upper edge of the trigger box 8 that the upper edge of the side walls of the trigger box 8 bears with a certain tension against the bearing surfaces 21 of the firearm casing 4. In this way a precise fixing of the position of the trigger box 8 in relation to the firearm casing 4 is obtained and the grip member 1 has a certain grip on the firearm casing 4 if it is not secured by means of the fastening pin.

By this construction it is relatively simple to maintain with great accuracy both the spacing of the bearing faces 21 on the firearm casing from the breech track defined by a rib 22 and also the spacing of the bearing points in the trigger box 8 from the upper edge of the side walls of this trigger box. Likewise it is the same for the spacing of the stop ledge 14 in relation to the locking position of the breech track as well as the bearing positions in relation to the front wall of the trigger box. In each case the stop surfaces are at the same time the reference lines by which the positions of the various parts of the trigger device can be measured so that no reference lines are involved which must be maintained by definite measurement which itself is already subject to a certain tolerance. Therefore the tolerances need not be made too restricted and moreover the maintenance of these tolerances is facilitated.

While the trigger box 8 has a definite position in relation to the firearm casing 4 in position of use of the grip member 1, the position of the grip member 1 in relation to the firearm casing 4 is completely uncritical. The box-like portion 7 of the grip member 1 which encloses the trigger box 8 fits over the edges of the adjacent portions of the magazine duct 2 and the firearm casing 4 as is indicated in dotted lines in FIG. 2. The portion 23 of the grip member 1 projecting rearwardly over the hand grip 5 is of U-shape in cross-section and surrounds the firearm casing 4 from beneath. At its rear end the firearm casing is of closed ring shape and the shoulder support 3 is inserted by a fitting projection in the rear end of the firearm casing 4.

This projection embodies a nose part 26 which bears on the rear wall of the trigger box 8 and thereby holds the trigger box in its position of use. The shoulder support 3 and the grip member 1 are held by means of holding pins 24 which are arranged over one another at the rear end of the firearm casing. The lower of these two holding pins penetrates also a bore 25 in the rear part 23 of the grip member 1 which corresponds with bores in the firearm casing 4 and in the shoulder support 3. It will be seen that after removal of the holding pins 24 the shoulder support can be withdrawn from the rear end of the firearm casing 4 and then the grip member 1 can be disengaged by a pull to the rear.

There is thus no danger that on releasing the shoulder support also the grip member 1 is automatically released since the frictional connection between the bearing surfaces 21 on the firearm casing 4 and the upper edge of the trigger box 8 is sufficient to hold the grip member 1 reliably in place.

Nevertheless the attachment and disengagement of the grip member by movement parallel to the firing direction is extremely simple and in particular no additional fastening pins are required for holding the grip member at its forward end, which could be lost on dismounting the grip member for servicing purposes. By the invention therefore because of the wide permissible tolerances a particularly simple, easily manipulated and easily manufactured arrangement or construction of the unit comprising the grip member and the trigger box as well as the adjacent parts of the firearm is obtained.

What we claim is:

1. Automatic hand firearm comprising a unit having a trigger box and a grip member releasably secured to the under side of a firearm casing and connected to the firearm casing by means of a fastening pin, means for releasably securing the trigger box at its upper edge by hook means at the forward and rear ends of the trigger box, facing in each case in the firing direction, said hook means engaging catch means fitted to the firearm casing and being held in their engaged positions by a nose part of a shoulder support and in which the trigger box is further provided in the region of its upper edge with bearing surfaces which rest against bearing surfaces of the firearm casing, which determine both the spacing of the unit from a breech track, and also their position in the direction of the breech track.

2. Hand firearm according to claim 1, characterized in that the unit rests against the under edges of the side walls of the firearm casing by the upper edge of the side walls of the trigger box thereof.

3. Hand firearm according to claim 1, characterized in that one catch means consists of a ledge provided on the firearm casing against which the front wall of the trigger box bears.

Hand firearm according to claim 2, characterized in that the trigger box is releasably secured in a grip member and the hook means are fitted to the trigger box.

5. Hand firearm according to claim 4, characterized in that the shoulder support has a nose part which holds the trigger box against the catch means of the firearm casing.

6. Hand firearm according to claim 1, characterized in that the hook means located at the forward end of the unit is formed by a projection at the upper edge of the front wall of the trigger box and this projection engages in a corresponding recess in the firearm casing.

7. Hand firearm according to claim 1, characterized in that the hook located at the rear end of the unit is formed by a portion of the rear wall of the trigger box which is extended upwardly above the side walls and bent forwardly and fits over a pin connecting the walls of the firearm casing. 

1. Automatic hand firearm comprising a unit having a trigger box and a grip member releasably secured to the under side of a firearm casing and connected to the firearm casing by means of a fastening pin, means for releasably securing the trigger box at its upper edge by hook means at the forward and rear ends of the trigger box, facing in each case in the firing direction, said hook means engaging catch means fitted to the firearm casing and being held in their engaged positions by a nose part of a shoulder support and in which the trigger box is further provided in the region of its upper edge with bearing surfaces which rest against bearing surfaces of the fiRearm casing, which determine both the spacing of the unit from a breech track, and also their position in the direction of the breech track.
 2. Hand firearm according to claim 1, characterized in that the unit rests against the under edges of the side walls of the firearm casing by the upper edge of the side walls of the trigger box thereof.
 3. Hand firearm according to claim 1, characterized in that one catch means consists of a ledge provided on the firearm casing against which the front wall of the trigger box bears.
 4. Hand firearm according to claim 2, characterized in that the trigger box is releasably secured in a grip member and the hook means are fitted to the trigger box.
 5. Hand firearm according to claim 4, characterized in that the shoulder support has a nose part which holds the trigger box against the catch means of the firearm casing.
 6. Hand firearm according to claim 1, characterized in that the hook means located at the forward end of the unit is formed by a projection at the upper edge of the front wall of the trigger box and this projection engages in a corresponding recess in the firearm casing.
 7. Hand firearm according to claim 1, characterized in that the hook located at the rear end of the unit is formed by a portion of the rear wall of the trigger box which is extended upwardly above the side walls and bent forwardly and fits over a pin connecting the walls of the firearm casing. 